Risk Factors and Outcomes of Nontuberculous Mycobacterial Disease among Rheumatoid Arthritis Patients: A Case-Control study in a TB Endemic Area

Proposed Etiotypes for Chronic Obstructive Pulmonary Disease: Controversial Issues

The 2023 Global Initiative for Chronic Obstructive Lung Disease (GOLD) revised the definition of chronic obstructive pulmonary disease (COPD) to broadly include a variety of etiologies. A new taxonomy, composed of etiotypes, aims to highlight the heterogeneity in causes and pathogenesis of COPD, allowing more personalized management strategies and emphasizing the need for targeted research to understand and manage COPD better. However, controversy arises with including some diseases under the umbrella term of COPD, as their clinical presentations and treatments differ from classical COPD, which is smoking-related. COPD due to infection (COPD-I) and COPD due to environmental exposure (COPD-P) are classifications within the new taxonomy. Some disease entities in these categories show distinct clinical features and may not benefit from conventional COPD treatments, raising questions about their classification as COPD subtypes. There is also controversy regarding whether bronchiectasis with airflow limitations should be classified as an etiotype of COPD. This article discusses controversial issues associated with the proposed etiotypes for COPD in terms of COPD-I, COPD-P, and bronchiectasis. While the updated COPD definition by GOLD 2023 is a major step towards recognizing the disease's complexity, it also raises questions about the classification of related respiratory conditions. This highlights the need for further research to improve our understanding and approach to COPD management.

Clinical characteristics and prognostic factors of non-tuberculous mycobacterial disease in patients with rheumatoid arthritis

BACKGROUND/AIMS

This study aimed to identify the clinical characteristics of patients with concurrent rheumatoid arthritis (RA) and suspected non-tuberculous mycobacterial (NTM) infections as well as determine their prognostic factors.

METHODS

We retrospectively reviewed the medical records of 91 patients with RA whose computed tomography (CT) findings suggested NTM infection. Subsequently, we compared the clinical characteristics between patients with and without clinical or radiological exacerbation of NTM-pulmonary disease (PD) and investigated the risk factors for the exacerbation and associated mortality.

RESULTS

The mean age of patients with RA and suspected NTM-PD was 65.0 ± 10.2 years. The nodular/bronchiectatic (NB) form of NTM-PD was the predominant radiographic feature (78.0%). During follow-up, 36 patients (41.9%) experienced a radiological or clinical exacerbation of NTM-PD, whereas 12 patients (13.2%) died. Combined interstitial lung disease (ILD), microbiologically confirmed NTM-PD, and NB with the fibrocavitary (FC) form on chest CT were identified as risk factors for the clinical or radiological exacerbation of NTM-PD. Hydroxychloroquine use was identified as a good prognostic factor. Conversely, history of tuberculosis, ILD, smoking, microbiologically confirmed NTM-PD, and NB with the FC form on chest CT were identified as poor prognostic factors for mortality in suspected NTM-PD.

CONCLUSION

ILD and NB with the FC form on chest CT were associated with NTM-PD exacerbation and mortality. Hydroxychloroquine use may lower the risk of NTM-PD exacerbation. Therefore, radiographic features and presence of ILD should be considered when predicting the prognosis of patients with RA and suspected NTM-PD.

Association of Tumor Necrosis Factor Inhibitors with the Risk of Nontuberculous Mycobacterial Infection in Patients with Rheumatoid Arthritis: A Nationwide Cohort Study

Tumor necrosis factor inhibitors (TNFi) are proposed as a risk factor for nontuberculous mycobacteria (NTM) infection. Limited research investigates NTM infection risk in rheumatoid arthritis (RA) patients treated with TNFi compared to conventional synthetic disease-modifying antirheumatic drugs (csDMARDs), considering other concurrent or prior non-TNFi antirheumatic drugs. We aimed to evaluate the NTM infection risk associated with TNFi using a real-world database. Patients with RA treated with TNFi or csDMARDs between 2005 and 2016 were identified utilizing the Korean National Health Insurance Service database. To minimize potential bias, we aligned the initiation year of csDMARDs for both TNFi and csDMARD users and tracked them from their respective treatment start dates. The association of TNFi with NTM infection risk was estimated in a one-to-one matched cohort using a multivariable conditional Cox regression analysis. In the matched cohort (n = 4556), the incidence rates of NTM infection were 2.47 and 3.66 per 1000 person-year in TNFi and csDMARD users. Compared to csDMARDs, TNFi did not increase the risk of NTM infection (adjusted hazard ratio (aHR) 0.517 (95% confidence interval, 0.205-1.301)). The TNFi use in RA patients was not associated with an increased risk of NTM infection compared to csDMARDs. Nevertheless, monitoring during TNFi treatment is crucial.

Clinical characteristics of rheumatoid arthritis patients complicated with pulmonary nontuberculous mycobacterial disease: A cross-sectional case series study

OBJECTIVES

Pulmonary nontuberculous mycobacterial disease (pNTM) is a common pulmonary complication of rheumatoid arthritis (RA), but their association has rarely been researched. We aimed to reveal the clinical characteristics of RA with pNTM.

METHODS

Among all the RA patients who visited Tenri hospital from April 2017 to March 2018, we enrolled those fulfilling the 2007 ATS/IDSA diagnostic criteria of pNTM, and sex- and age- matched control group at a ratio of 1:5. Demographic characteristics were compared between the two groups.

RESULTS

Among 865 RA patients, 35 (4.0%) patients were complicated with pNTM. RA patients with pNTM had significantly lower BMI and higher rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) positivity. Bronchiectasis was the most frequent lesion, followed by clusters of small nodules, patchy consolidation and cavity. Multivariable logistic regression analysis revealed bronchiectasis as a strong independent associated factor of pNTM. Treatment for pNTM was needed in 14 of the 35 (40%) RA patients with pNTM and sputum negative conversion was accomplished in 11 of the 14 cases (78.6%).

CONCLUSIONS

RA patients with lower BMI, RF/ACPA positivity, and bronchiectasis were associated with pNTM. Treatment for pNTM may attain sputum negative conversion and radiological improvement in patients with RA.

Disseminated Mycobacterium chelonae infection complicating rheumatoid arthritis: A case report and review of the literature

INTRODUCTION

Rheumatoid arthritis (RA) may predispose patients to opportunistic infections-either from innate immune dysregulation, or as a result of immunosuppressant use to treat the RA. Particularly concerning opportunistic infections are those caused by non-tuberculous mycobacterial (NTM) organisms, the incidence of which has been increasing in epidemiological studies. Despite this, guidelines on the management of patients with RA who develop NTM infections are scarce, particularly with respect to immunosuppressant regimen modulation and duration of antibiotic therapy.

CASE REPORT

Herein, we present a case of disseminated Mycobacterium chelonae infection, manifesting as arthralgia and cutaneous nodules.

DISCUSSION

In addition, a review of the literature was conducted to Preferred Reporting Items for Systemic Reviews and Meta-Analyses guidelines to identify similar cases in the literature-revealing that all RA-associated M. Chelonae infections occurred in immunosuppressed patients (the majority with corticosteroids or tumor necrosis factor inhibitors), and considerable heterogeneity in management approaches. Further research regarding risk factors, preventative approaches and best management of such NTM infections in vulnerable patients with RA is required in order to establish consensus guidelines and consistency.

Mycobacterium xenopi infection of the kidney and lymph nodes: A case report

The incidence of nontuberculous mycobacterial (NTM) infection has been increasing globally. Further, it has been reported that early NTM infection diagnosis and treatment can considerably improve patient prognosis. However, traditional methods for detecting pathogenic microorganisms are associated with several limitations, and optimal treatment regimens for several NTM infections have not yet been established. Here, we report the case of a 22-year-old woman with renal and lymph node Mycobacterium xenopi infection. This patient presented with repeated fever and systemic lymphadenopathy events for more than 2 years, but the etiology of the disease was unclear. We performed metagenomic next-generation sequencing (mNGS) using tissue sections from the patient's left kidney and successfully identified M. xenopi. Thereafter, the patient's condition was effectively controlled via treatment with rifampicin, clarithromycin, and ethambutol hydrochloride (orally administered after hemodialysis). Further, this case showed that the clinical symptoms of NTM infection are atypical and highly occult, especially for extrapulmonary NTM infections, which are difficult to diagnose. Therefore, mNGS may be a powerful tool for diagnosing NTM infections. The combination therapy used showed efficacy and thus could serve as a reference treatment for kidney and lymph node M. xenopi infection.

Non-tuberculous mycobacteria pulmonary disease: A review of trends, risk factors, diagnosis and management

Non-tuberculous mycobacteria (NTM) reports have been on the rise globally, with increasing incidence and prevalence accompanied by poor outcomes. The rise has been attributed to an ageing population with increasing comorbid illnesses, and improved laboratory techniques in diagnosing the disease. However, despite the increase, some parts of the world still lack data, especially sub-Saharan African countries. The lack of data in our setting is difficult to explain, as we have a significant burden of NTM risk factors (i.e. HIV, tuberculosis and bronchiectasis). This review therefore serves as a reminder and a challenge to start searching, and reporting on our experiences. The review will highlight the rising incidence, important risk factors, diagnosis and management of NTM pulmonary disease.

Risk Factors for the Development of Nontuberculous Mycobacteria Pulmonary Disease during Long-Term Follow-Up after Lung Cancer Surgery

The aim of this study is to determine the cumulative incidence of, and the risk factors for, the development of nontuberculous mycobacteria pulmonary disease (NTM-PD) following lung cancer surgery. We retrospectively analyzed patients with non-small cell lung cancer who underwent surgical resection between 2010 and 2016. Patients who met all the diagnostic criteria in the NTM guidelines were defined as having NTM-PD. Additionally, we classified participants as NTM-positive when NTM were cultured in respiratory specimens, regardless of the diagnostic criteria. We followed 6503 patients for a median of 4.89 years, and NTM-PD and NTM-positive diagnoses occurred in 59 and 156 patients, respectively. The cumulative incidence rates of NTM-PD and NTM-positive were 2.8% and 5.9% at 10 years, respectively. Mycobacterium avium complex was the most commonly identified pathogen, and half of the NTM-PD patients had cavitary lesions. Several host-related factors (age > 65 years, body mass index ≤ 18.5 kg/m2, interstitial lung disease, bronchiectasis, and bronchiolitis) and treatment-related factors (postoperative pulmonary complications and neoadjuvant/adjuvant treatments) were identified as risk factors for developing NTM-PD and/or being NTM-positive after lung cancer surgery. The incidences of NTM-PD and NTM-positive diagnoses after lung cancer surgery were not low, and half of the NTM-PD patients had cavitary lesions, which are known to progress rapidly and often require treatment. Therefore, it is necessary to raise awareness of NTM-PD development after lung cancer surgery.

TNF inhibitors increase the risk of nontuberculous mycobacteria in patients with seropositive rheumatoid arthritis in a mycobacterium tuberculosis endemic area

The aim of this study is to examine the impact of tumor necrosis factor inhibitors (TNFI) on nontuberculous mycobacterium (NTM) infection in rheumatoid arthritis (RA) patients in a mycobacterium tuberculosis (MTB) endemic area. We selected 1089 TNFI-treated RA patients and 4356 untreated RA patients using propensity-matching analysis according to age, gender, and Charlson comorbidity index using the Korean National Health Insurance Service database from July 2009 to December 2010. Both groups were followed-up until the end of 2016 to measure the incidence of mycobacterial diseases. The incidence rate of NTM in TNFI-treated RA group was similar to those of MTB (328.1 and 340.9 per 100,000 person-years, respectively). The adjusted hazard ratio (aHR) of NTM for TNFI-treated RA compared to untreated RA was 1.751(95% CI 1.105-2.774). The risk of TNFI-associated NTM in RA was 2.108-fold higher among women than men. The age-stratified effects of TNFI on NTM development were significantly high in RA patients aged 50-65 years (aHR 2.018). RA patients without comorbidities had a higher incidence of NTM following TNFI treatment (aHR 1.742). This real-world, observational study highlights the need to increase awareness of NTM in TNFI-treated RA patients in an MTB endemic area.

Neglected tropical rheumatic diseases

The complexities of dealing with rheumatic diseases in tropical countries are diverse and likely due to limited health care infrastructure, lack of diagnostic and therapeutic facilities, impact of dominant prevailing diseases, and the challenges of differentiating from infectious and non-infectious disease mimics. Several tropical diseases present with musculoskeletal and rheumatic manifestations and often pose a diagnostic dilemma to rheumatologists. The diagnosis is often delayed or the disease is misdiagnosed, leading to poor patient outcomes. Endemic tropical diseases like tuberculosis and leprosy have myriad rheumatic presentations and remain important differentials to consider in patients with rheumatic manifestations. Infection with human immunodeficiency virus is a great masquerade and can mimic manifestations of multiple diseases. The role of viral infections in triggering and perpetuating autoimmunity is well known and chikungunya arthritis is a classic example of the same. This review highlights the rheumatic manifestations of tropical diseases and aims to create awareness among the caregivers. Key Points • It is crucial to be aware and identify infectious diseases presenting with rheumatic manifestations in the tropics. • Presentations akin to classic rheumatic syndromes such as rheumatoid arthritis, spondyloarthritis, systemic lupus erythematosus and vasculitis are common.

The key factors contributing to the risk, diagnosis and treatment of non-tuberculous mycobacterial opportunistic infections

The incidence and prevalence of diseases caused by non-tuberculous mycobacteria (NTM) have been steadily increasing worldwide. NTM are environmental saprophytic organisms; however, a few strains are known to produce diseases in humans affecting pulmonary and extra-pulmonary sites. Although the environment is a major source of NTM infection, recent studies have shown that person-to-person dissemination could be an important transmission route for these microorganisms. Structural and functional lung defects and immunodeficiency are major risk factors for acquiring NTM infections. Diagnosis of NTM diseases is very complex owing to the necessity of distinguishing between a true pathogen and an environmental contaminant. Identification at the species level is critical due to differences in the antibiotic susceptibility patterns of various NTM strains. Such identification is mainly achieved by molecular methods; additionally, mass spectrometry (e.g., MALDI-TOF) is useful for NTM species determination. Natural resistance of NTM species to a wide spectrum of antibiotics makes prescribing treatment for NTM diseases very difficult. NTM therapy usually takes more than one year and requires multi-drug regimens, yet the outcome often remains poor. Therefore, alternatives to antibiotic therapy treatment methods is an area under active exploration. NTM infections are an active global health problem imposing the necessity for better diagnostic tools and more effective treatment methods.

Short-term tolerability and effectiveness of methotrexate monotherapy in adult patients with Crohn's disease: a retrospective study

INTRODUCTION

Immunomodulators remain fundamental for the medical treatment of Crohn's disease (CD). Methotrexate (MTX) is widely used as a second-line immunomodulator; however, there is a lack of recent data on MTX monotherapy among the Asian population with CD. Therefore, in this study, we aimed to investigate the tolerability and clinical outcomes of MTX in Korean patients with CD.

METHODS

A retrospective chart review was performed for CD patients treated with MTX monotherapy or in combination with 5-aminosalicylic acid (5-ASA), at the Asan Medical Center, Seoul, South Korea. The tolerability of MTX monotherapy within 6 months was assessed and the clinical effectiveness of MTX was evaluated based on the Crohn's disease activity index (CDAI).

RESULTS

In total, 85 patients were included, of which 29 (34.1%) discontinued MTX due to intolerability during the follow-up. Adverse events (AEs) were reported in 41 (48.2%) patients. The most common AE was gastrointestinal disorders (17/41) and only one patient experienced a serious AE, a systemic infection that required hospitalization. Among the 56 patients who tolerated MTX within 6 months, 44 (65.9%) showed a clinical response. Moreover, no factor was significantly associated with intolerability. The administration method was the only factor significantly associated with a response to MTX (p = 0.041). The adjusted odds ratio of parenteral injection compared to oral administration was 5.68 (95% confidence interval (CI), 1.07-30.08).

CONCLUSION

In this study, one-third of patients were intolerant to MTX; nonetheless, the response rate was as high as 65.9% among tolerant patients. In addition, no significant factors affected intolerability. In terms of the clinical response, parenteral injection could be better than oral administration.

Simultaneous treatment for M ycobacterium-avium complex lung disease and allergic bronchopulmonary aspergillosis: A case report

Recently, there are several reports of simultaneous allergic bronchopulmonary aspergillosis (ABPA) and Mycobacterium-avium complex (MAC) lung disease. However, the strategies for early diagnosis and appropriate treatment for patients with both ABPA and MAC lung disease have not been established. Here, we report a case with ABPA complicated by MAC lung disease, which was successfully diagnosed and treated by simultaneous administration of systemic steroids and antimycobacterial drugs. Bronchoscopy can be useful in the diagnosis of such cases. Furthermore, in a patient with concurrent ABPA and MAC lung disease, simultaneous treatments for both diseases could reduce both diseases.

2021 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis

OBJECTIVE

To develop updated guidelines for the pharmacologic management of rheumatoid arthritis.

METHODS

We developed clinically relevant population, intervention, comparator, and outcomes (PICO) questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to rate the certainty of evidence. A voting panel comprising clinicians and patients achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations.

RESULTS

The guideline addresses treatment with disease-modifying antirheumatic drugs (DMARDs), including conventional synthetic DMARDs, biologic DMARDs, and targeted synthetic DMARDs, use of glucocorticoids, and use of DMARDs in certain high-risk populations (i.e., those with liver disease, heart failure, lymphoproliferative disorders, previous serious infections, and nontuberculous mycobacterial lung disease). The guideline includes 44 recommendations (7 strong and 37 conditional).

CONCLUSION

This clinical practice guideline is intended to serve as a tool to support clinician and patient decision-making. Recommendations are not prescriptive, and individual treatment decisions should be made through a shared decision-making process based on patients' values, goals, preferences, and comorbidities.

2021 American College of Rheumatology Guideline for the Treatment of Rheumatoid Arthritis

OBJECTIVE

To develop updated guidelines for the pharmacologic management of rheumatoid arthritis.

METHODS

We developed clinically relevant population, intervention, comparator, and outcomes (PICO) questions. After conducting a systematic literature review, the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to rate the certainty of evidence. A voting panel comprising clinicians and patients achieved consensus on the direction (for or against) and strength (strong or conditional) of recommendations.

RESULTS

The guideline addresses treatment with disease-modifying antirheumatic drugs (DMARDs), including conventional synthetic DMARDs, biologic DMARDs, and targeted synthetic DMARDs, use of glucocorticoids, and use of DMARDs in certain high-risk populations (i.e., those with liver disease, heart failure, lymphoproliferative disorders, previous serious infections, and nontuberculous mycobacterial lung disease). The guideline includes 44 recommendations (7 strong and 37 conditional).

CONCLUSION

This clinical practice guideline is intended to serve as a tool to support clinician and patient decision-making. Recommendations are not prescriptive, and individual treatment decisions should be made through a shared decision-making process based on patients' values, goals, preferences, and comorbidities.

The Role of Lung Colonization in Connective Tissue Disease-Associated Interstitial Lung Disease

Connective tissue diseases (CTDs) may frequently manifest with interstitial lung disease (ILD), which may severely impair quality and expectation of life. CTD-ILD generally has a chronic clinical course, with possible acute exacerbations. Although several lines of evidence indicate a relevant role of infections in the acute exacerbations of CTD-ILD, little information is available regarding the prevalence of infections in chronic CTD-ILD and their possible role in the clinical course. The aim of the present retrospective study was the identification of lung microbial colonization in broncho-alveolar lavage from patients affected by stable CTD-ILD with radiologically defined lung involvement. We demonstrated that 22.7% of patients with CTD-ILD display microbial colonization by Pseudomonas aeruginosa, Haemophilus influenzae, and non-tuberculous mycobacteria. Moreover, these patients display a major radiologic lung involvement, with higher impairment in lung function tests confirmed in a multivariate logistic regression analysis. Overall, the present study provides new information on lung colonization during CTD-ILD and its possible relationship with lung disease progression and severity.

Mycobacterial Infections Potentiated by Biologics

Biologic therapies have revolutionized the treatment of immune-mediated inflammatory diseases but are associated with an increased risk of serious and opportunistic infections, including tuberculosis and nontuberculous mycobacterial disease. Despite this increased risk, the overall risk-benefit ratio remains favorable with appropriate screening and risk assessment. Further population-based studies are needed to establish the risk of tuberculosis and nontuberculous mycobacterial disease with the new biologics. This article highlights the incidence and drug-specific risk of tuberculous and nontuberculous mycobacterial infection in the setting of biologics, screening and prevention, and treatment of latent tuberculosis in this setting.

Mortality in rheumatoid arthritis patients with pulmonary nontuberculous mycobacterial disease: A retrospective cohort study

Objective

The aim of this study was to compare long-term mortality following diagnosis of pulmonary nontuberculous mycobacterial (NTM) disease between patients with and without rheumatoid arthritis (RA) and to evaluate predictive factors for death outcomes.

Methods

We reviewed the electronic medical records of all patients who were newly diagnosed with pulmonary NTM disease at participating institutions between August 2009 and December 2018. Patients were followed until death, loss to follow-up, or the end of the study. Taking into consideration the presence of competing risks, we used the cumulative incidence function with Gray’s test and Fine-Gray regression analysis for survival analysis.

Results

A total of 225 patients (34 RA patients and 191 non-RA controls) were followed, with a mean time of 47.5 months. Death occurred in 35.3% of RA patients and 25.7% of non-RA patients. An exacerbation of pulmonary NTM disease represented the major cause of death. The estimated cumulative incidence of all-cause death at 5 years was 24% for RA patients and 23% for non-RA patients. For NTM-related death, the 5-year cumulative incidence rate was estimated to be 11% for RA patients and 18% for non-RA patients. Gray’s test revealed that long-term mortality estimates were not significantly different between patient groups. Fine-Gray regression analysis showed that the predictive factors for NTM-related death were advanced age (adjusted hazards ratio 7.28 [95% confidence interval 2.91–18.20] for ≥80 years and 3.68 [1.46–9.26] for 70–80 years vs. <70 years), male sex (2.40 [1.29–4.45]), Mycobacterium abscessus complex (4.30 [1.46–12.69] vs. M. avium), and cavitary disease (4.08 [1.70–9.80]).

Conclusions

RA patients with pulmonary NTM disease were not at greater risk of long-term mortality compared with non-RA patients. Rather, advanced age, male sex, causative NTM species, and cavitary NTM disease should be considered when predicting the outcomes of RA patients with pulmonary NTM disease.

Clinical relevance and diagnosis of nontuberculous mycobacterial pulmonary disease in populations at risk

The lungs are the most common disease site of nontuberculous mycobacteria (NTM). However, the isolation of NTM in a respiratory specimen does not indicate lung disease (LD). Differentiation between NTM colonization and NTM-LD remains challenging. In this brief review, we summarize the clinical impact of NTM-LD on morbidity and mortality in high-risk populations. The diagnosis criteria for NTM-LD-including clinical features, radiological presentations, and microbiological evidence-are also reviewed, according to the latest American Thoracic Society (ATS)/Infectious Disease Society of America (IDSA) guideline and the British Thoracic Society (BTS) guideline. However, the diagnosis of NTM-LD does not necessitate the initiation of anti-NTM treatment. Both environmental, host, and bacterial factors should be considered to identify patients that require NTM-LD treatment.

The Rise of Non-Tuberculosis Mycobacterial Lung Disease

The incidence and number of deaths from non-tuberculous mycobacterial (NTM) disease have been steadily increasing globally. These lesser known “cousins” of Mycobacterium tuberculosis (TB) were once thought to be harmless environmental saprophytics and only dangerous to individuals with defective lung structure or the immunosuppressed. However, NTM are now commonly infecting seemingly immune competent children and adults at increasing rates through pulmonary infection. This is of concern as the pathology of NTM is difficult to treat. Indeed, NTM have become extremely antibiotic resistant, and now have been found to be internationally dispersed through person-to-person contact. The reasons behind this NTM increase are only beginning to be elucidated. Solutions to the problem are needed given NTM disease is more common in the tropics. Importantly, 40% of the world's population live in the tropics and due to climate change, the Tropics are expanding which will increase NTM infection regions. This review catalogs the global and economic disease burden, at risk populations, treatment options, host-bacterial interaction, immune dynamics, recent developments and research priorities for NTM disease.

Can environmental determinants explain Nontuberculous Mycobacteria geographic incidence?

INTRODUCTION AND OBJECTIVES

Nontuberculous mycobacteria (NTM) are opportunistic agents that have gained importance during the last decades due to their increasing incidence in high-risk populations. Their modes of transmission differ from person-toperson contact commonly described in Mycobacterium tuberculosis (MTB). In fact, NTM are frequently found in soil, natural waters and drinking-water distributions systems, emphasizing the contribution of environmental factors when discussing this disease's susceptibility. Our aim is to evaluate the incidence of NTM in Portugal and to identify the main environmental variables related to it.

MATERIAL AND METHODS

We performed a cross-sectional study centred on 2011 (date of the latest Portuguese census) from collected personal features and environmental data available in public databases. Environmental values when only known at the district level were interpolated using inverse distance weighting. A semiparametric poisson model was used to estimate NTM incidence. The non-parametric part of the model was obtained by using thin plate smoothing splines defined on the spatial component of the data.

RESULTS

359 new NTM cases were notified during a five-year period. None of the environmental determinants studied was strong enough to predict NTM geographical incidence in Portugal (p>0.05), except for population density (p<0.001). Personal characteristics such as female sex (p<0.001), age (p<0.001) and Human Immunodeficiency Virus infection and Acquired Immune Deficiency Syndrome (HIV/AIDS) incidence (p<0.001) are associated with an increase of NTM disease incidence.

CONCLUSIONS

NTM appears to be more common in elderly women, especially if they have HIV/AIDS disease or if they live in urban, highly populated areas. Overall, female sex seems to assume the most relevant role when discussing predisposition to NTM disease. However, further studies are needed to evaluate the impact on NTM geographical incidence by other environmental and personal variables not included in this one.

Mycobacterium avium complex pulmonary disease: new epidemiology and management concepts

PURPOSE OF REVIEW

The prevalence of Mycobacterium avium complex (MAC)-related pulmonary disease has been increasing because of environmental factors, changes in organism virulence, and evolving host susceptibility. Treatment is often complicated by adverse effects, development of drug resistance, and refractory disease, with recurrence rates as high as 25-45%.

RECENT FINDINGS

Aerosolization of water, soil, or dusts are the likely sources of MAC-related pulmonary disease in susceptible individuals. The management of MAC-related pulmonary disease requires a multimodality approach, including antimicrobial therapy in appropriate patients, employment of mucus clearance techniques, instituting changes in the individual's home environment and personal habits to reduce environmental exposure to MAC, prevention of reflux, and maintenance of a healthy body weight. When the standard treatment for MAC-related pulmonary disease is not possible because of drug intolerance, antibiotic resistance, or progression of disease, second-line agents such as inhaled amikacin, clofazimine, bedaquiline, and delamanid must be considered, despite limited experience and few studies to guide their use.

SUMMARY

Individuals who have proven to be susceptible to MAC-related pulmonary disease should institute measures to reduce exposure to environmental sources of infection. Further research is needed to assess the impact of such preventive strategies on the incidence of new infection and disease recurrence. The efficacy of new medications for MAC-related pulmonary disease and their use in different combinations also requires further study.

Non-tuberculous mycobacterial pulmonary disease

Nontuberculous mycobacterial pulmonary disease (NTM-PD) is a challenging infection which is becoming increasingly prevalent, particularly in the elderly, for reasons which are unknown. While underlying lung disease is a well-established risk factor for NTM-PD, it may also occur in apparently healthy individuals. No single common genetic or immunological defect has been identified in this group, and it is likely that multiple pathways contribute towards host susceptibility to NTM-PD which further interact with environmental and microbiological factors leading to the development of disease.The diagnosis of NTM-PD relies on the integration of clinical, radiological and microbiological results. The clinical course of NTM-PD is heterogeneous, with some patients remaining stable without the need for treatment and others developing refractory disease associated with considerable mortality and morbidity. Treatment regimens are based on the identity of the isolated species, drug sensitivity testing (for some agents) and the severity of disease. Multiple antibiotics are typically required for prolonged periods of time and treatment is frequently poorly tolerated. Surgery may be beneficial in selected cases. In some circumstances cure may not be attainable and there is a pressing need for better regimens to treat refractory and drug-resistant NTM-PD.This review summarises current knowledge on the epidemiology, aetiology and diagnosis of NTM-PD and discusses the treatment of two of the most clinically significant species, the M. avium and M. abscessus complexes, with a focus on refractory disease and novel therapies.

Inflammatory bowel disease and mycobacteria: how much can we trust isoniazid prophylaxis during antitumor necrosis factor therapy?

OBJECTIVES

Isoniazid (INH) prophylaxis is recommended for the prevention of tuberculosis (TB) reactivation before or/and during initiation of treatment with tumour necrosis factor antagonists (anti-TNF agents). Nonetheless, the long-term effectiveness of chemoprophylaxis is not clear. In this study, we aimed to evaluate the characteristics of patients who developed TB reactivation in spite of INH prophylaxis associated with anti-TNF treatment.

PATIENTS AND METHODS

In this retrospective study, medical records of 1263 patients with inflammatory bowel disease were reviewed. Baseline TB screening tests (purified protein derivative test and/or QuantiFERON-TB Gold test) were performed on all patients before initiation of anti-TNF therapy. Patients with purified protein derivative of more than 5 mm and/or a positive result of the QuantiFERON-TB Gold test received INH prophylaxis for 9 months. We analysed the data of patients diagnosed with TB reactivation during the anti-TNF treatment despite INH chemoprophylaxis.

RESULTS

Overall, 175 patients underwent anti-TNF treatment. Sixty of these 175 patients had pretreatment testing showing latent TB infection and therefore were treated concomitantly with INH for 9 months in addition to their anti-TNF treatment. TB reactivation occurred in four of these 60 co-INH/anti-TNF treated patients. Active TB was diagnosed after 37.5±27 (range: 18-84) months of anti-TNF treatment. In two of the four patients that active TB was diagnosed, was also detected other Mycobacterium spp.: M. bovis in one patient and M. genavense in the other one.

CONCLUSION

INH chemoprophylaxis may not prevent the reactivation of TB during anti-TNF therapy in the long-term. Patients should be carefully and periodically screened for TB reactivation during anti-TNF therapy.

Successful treatment with mepolizumab in a case of allergic bronchopulmonary aspergillosis complicated with nontuberculous mycobacterial infection

Allergic bronchopulmonary aspergillosis (ABPA) is a complex hypersensitivity reaction that is associated with an allergic immunological response to Aspergillus species via Th2-related inflammation. The long-term use of a systemic corticosteroid is often needed for the treatment of ABPA. However, systemic corticosteroid treatment imposes a risk of the onset of a nontuberculous mycobacterial infection. Here we report the case of a patient with ABPA who required the long-term use of an oral corticosteroid because her repeated asthmatic attacks were successfully treated with mepolizumab, an anti-interleukin-5 monoclonal antibody. The patient, a 60-year-old Japanese female, had been treated with an oral corticoid and itraconazole. Despite the success of the initial treatment for ABPA, it was difficult to discontinue the use of the oral corticosteroid. In addition, Mycobacterium avium was detected from her bronchial lavage. We initiated mepolizumab treatment to taper the amount of corticosteroid and control the asthma condition. The patient's number of blood eosinophils, serum IgE level, fractional exhaled nitric oxide level, dosage of oral prednisolone, and need for inhaled budesonide/formoterol all improved, without an exacerbation of her asthma attacks. Although further research regarding mepolizumab treatment is needed, we believe that mepolizumab could be considered one of the agents for treating refractory ABPA.

The complexities and challenges of preventing and treating nontuberculous mycobacterial diseases

Seemingly innocuous nontuberculous mycobacteria (NTM) species, classified by their slow or rapid growth rates, can cause a wide range of illnesses, from skin ulceration to severe pulmonary and disseminated disease. Despite their worldwide prevalence and significant disease burden, NTM do not garner the same financial or research focus as Mycobacterium tuberculosis. In this review, we outline the most abundant of over 170 NTM species and inadequacies of diagnostics and treatments and weigh the advantages and disadvantages of currently available in vivo animal models of NTM. In order to effectively combat this group of mycobacteria, more research focused on appropriate animal models of infection, screening of chemotherapeutic compounds, and development of anti-NTM vaccines and diagnostics is urgently needed.

Risk of mycobacterial disease among cancer patients: A population-based cohort study in a TB endemic area

OBJECTIVES

Tuberculosis (TB) and nontuberculous mycobacteria (NTM) disease have similar symptoms, which makes them difficult to distinguish clinically and leads to the danger of NTM disease being neglected. The aim of this study was to assess the risk of developing mycobacterial disease among cancer patients.

METHODS

We conducted a retrospective cohort study using a population-based database. The multivariable Cox proportional hazards model was adjusted to identify independent factors contributing to the development of mycobacterial disease in the cancer cohort.

RESULTS

The results showed that the increased risk of developing TB and NTM disease was 1.84-fold and 4.43-fold, respectively, in cancer patients compared with the general population. Advanced age (≥65years) and being male were risk factors for developing TB disease. There was a 4.09-fold significantly increased risk of TB disease within six months of a cancer diagnosis. Hematological cancer patients were most likely to develop mycobacterial disease. Younger hematological cancer patients (< 45years) had a higher risk of NTM disease development.

CONCLUSION

There is an increasing risk of mycobacterial disease in cancer patients. We suggest that the possibility of mycobacterial disease in cancer patients should be assessed during the period of cancer therapy, particularly in those who have risk factors.

[Nontuberculous mycobacterial infections]

Nontuberculous mycobacterial (NTM) are found ubiquitously in the environment and are usually of low pathogenicity. Infection occurs via inhalation of aerosols, and some species may cause severe infections. The incidence of NTM infections is rising worldwide. The risk of developing NTM disease depends on the susceptibility of the host as well as the frequency and duration of exposure. In addition to congenital immune deficiencies and immunosuppressive therapy, structural lung and systemic diseases, including rheumatoid arthritis (RA), are associated with an increased risk for NTM infections. The immune response to NTM is complex and relies on the interplay between professional phagocytes and lymphoid cells. This interplay is concerted by three key cytokines: interleukin-12 (IL-12), tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ). Targeted immunotherapies, e. g., treatment with TNF inhibitors, interfere with these essential pathways and increase the risk of NTM infection significantly. This review focuses on the relationship between the immune response to NTM and intrinsic and iatrogenic dispositions for NTM infection, with an emphasis on RA.

Selective antibody activation through protease-activated pro-antibodies that mask binding sites with inhibitory domains

Systemic injection of therapeutic antibodies may cause serious adverse effects due to on-target toxicity to the antigens expressed in normal tissues. To improve the targeting selectivity to the region of disease sites, we developed protease-activated pro-antibodies by masking the binding sites of antibodies with inhibitory domains that can be removed by proteases that are highly expressed at the disease sites. The latency-associated peptide (LAP), C2b or CBa of complement factor 2/B were linked, through a substrate peptide of matrix metalloproteinase-2 (MMP-2), to an anti-epidermal growth factor receptor (EGFR) antibody and an anti-tumor necrosis factor-α (TNF-α) antibody. Results showed that all the inhibitory domains could be removed by MMP-2 to restore the binding activities of the antibodies. LAP substantially reduced (53.8%) the binding activity of the anti-EGFR antibody on EGFR-expressing cells, whereas C2b and CBa were ineffective (21% and 9.3% reduction, respectively). Similarly, LAP also blocked 53.9% of the binding activity of the anti-TNF-α antibody. Finally, molecular dynamic simulation showed that the masking efficiency of LAP, C2b and CBa was 33.7%, 10.3% and −5.4%, respectively, over the binding sites of the antibodies. This strategy may aid in designing new protease-activated pro-antibodies that attain high therapeutic potency yet reduced systemic on-target toxicity.

The impact of cancer development on the risk of mycobacterial diseases among rheumatoid arthritis patients

Mycobacterial diseases are prevalent in cancer and rheumatoid arthritis (RA) patients, especially those receiving tumor necrosis factor-α inhibitor (TNFi). However, the impact of cancer development on the risk of mycobacterial diseases among RA patients is unknown. Data from the Taiwan National Health Insurance Research Database were used to conduct a retrospective study to assess the occurrence of mycobacterial diseases in RA patients developing cancer (cancer-positive), those using TNFi (TNFi-exposure), those with cancer and using TNFi (cancer-TNFi-comb), and those without cancer and not using TNFi (cancer-TNFi-free). Cancer and TNFi exposure were time-dependent, and independent risk factors of mycobacterial diseases were assessed by Cox regression. Among 1344 RA patients diagnosed during 2000–2013, 68 (5·1%) developed cancer before their end points. The incidence rates of mycobacterial diseases in the cancer-positive (n = 56), TNFi-exposure (n = 290), cancer-TNFi-comb (n = 12), and cancer-TNFi-free (n = 986) subgroups were 6·7, 2·0, 7·6, and 1·3 per 1000 person-years, respectively. As compared with the cancer-TNFi-free group, the risk for mycobacterial diseases increased for the TNFi-exposure group (adjusted HR = 3·6, 95% confidence interval (95% CI) 1·1–11·5, P = 0·032) and remained high for cancer-positive (adjusted HR = 14·6, 95% CI 3·3–63·7, P < 0·001) after adjustment. This study suggested that cancer development increased the risk of mycobacterial diseases in RA patients, and risk assessment for this subgroup should be considered.